2.In what way does the film music from different movie genres differ, based on the emotional quadrant?

Select movie genre:

Mode 0 = minor, mode 1 = major

This graphic shows the emotional quadrant of tracks played in movies from movie genres Horror, Action, Feelgood/Comedy and Romance/Drama with color representing the mode and size the loudness of the track Valence describes the musical positiveness, energy describes the arousal. There is a clear distinction of the Horror and Action genres from the other two, the tracks are mainly displayed on very low valence values. Most of the tracks from Horror movies are concentrated in the Depressing/Sad section of the emotional quadrant graph, with a lot of minor songs and these are overall very ‘quiet’, which is represented by the size of the dots. The bigger the dot, the louder the song. Tracks from Action movies are more smeared out, but locate mainly in the Angry/Turbulent and Depressing/Sad sections of the graph. Surprisingly, the majority of these tracks do not seem to be very loud at all, which is in contrast with the expectations. Feelgood-Comedy tracks are more scattered, but in comparison with the other genres, this genre has a lot of tracks in the Happy/Joyful section with more louder songs, which is in line with the expectations. The tracks of Romantic/Drama’s are localized throughout the whole plot, but do have a low valence overall.

Select specific movies:

What about tempo? Is there a difference between genres and minor & major keys?

On average, feelgood/comedy movies have a higher BPM than the other three genres (+/- 120 BPM). The average BPM for horror movies is the lowest (around 90 BPM). The distribution for romance/drama and action is about the same. It is also clear that overall, songs in minor key do have a slightly lower BPM than major-key songs, especially in action movies.

Self-similarity matrices of ‘Feelgood’ and ’Another dance", typical comedy and romantic tracks

The differences between a typical Horror track a typical track from a Feelgood/Comedy movie based on chroma features

The differences of timbral components of an outlier and a typical track in horror film-music [Cepstrograms]

Timbre, also known as “tone color”, is the perceived sound quality of a musical note or sound. It distinguishes various types of musical instruments. There are twelve timbre coefficients in total. the values are high level abstractions of the spectral surface ordered by degree of importance. The first coefficient represents the ‘average loudness’, the second points out ‘brightness’, the third is more closely related to the ‘flatness’ of a sound and the fourth to sounds with a ‘stronger attack’. Increased levels of mid and high frequency content are referred to as ‘brighter’. A high flatness indicates that the spectrum has a similar amount of power in all spectral bands (i.e. similar to white noise) and low flatness indicates a “spiky” spectrum (mixture of sine waves).

From the graph of Doll Box, it is very clear which timbre components are being used in this track; c02, c03 and c04. The sound of this track represents the typical sound of a doll music box. Because these three components are very constant throughout the whole track, it is hard to distinguish the different sound characteristics. Two clear spots in this cepstrogram, are the very contrasting parts at t = 1 and at t = 32. These parts are riffs on a copper xylophone.

As you can see, the timbral components of Curse Your Name are much more spread out in the cepstrogram. This is very typical in horror music, because horror music tends to have a lot of different musical characteristics/instruments played at the same time, that seeks to give the audience an uncomfortable and unsettling feeling. The first bright yellow part of co2 is very distinguishable in this track. It represents a wind-instrument, probably a trumpet. Immediately after this part, a somewhat longer c01 appears. This part is a very low-pitched string-instrument, it sounds like a string bass. The yellow part of c05 is a very sharp sound, a high-pitched flute which is very unpleasant to the ear. It is clear that both very high- and low pitched sounds are being used at the same time in typical horror music.

When comparing c03 in both tracks: this sound is in both tracks a very high-pitched instrument, however, in doll house this sound is made by a percussion instrument. In Curse Your Name, this sound sounds more like a wind instrument.

The mean differences of timbre coefficients of each movie genre

For this analysis, the first 80 tracks from each genre was being used

When comparing the twelve Spotify timbre coefficients between the four movie genres, the main difference lies in the second and third coefficient. For c02, horror music really differs from the other genres. It seems that the range is way more in the positive area. This is probably due to the use of stringed instruments in horror music.

1. Is it possible to predict movie genre based on only music score?

The analysis is performed over 120 tracks from each genre category

Genre classification with all four genres was performed using support vector machines in a ten-fold cross-validation test. Here, three confusion matrices from all features (track-level-, timbral- and chroma features), timbral features and chroma features are being compared. The darker the color grey, the better the prediction of the tracks.

2. What musical features really do characterize movie genre?

From the forest model, it is very clear that there are some features that really characterize the four movie genres. The top 6 features are:

3. Confusion matrix with characterizing components

When looking only at the top 8 components from the previous page and compare it with the other:

4. Decision Tree

From the decision tree, the precision and recall for the different genres are much better than the ones for the confusion matrices. Recall (sensitivity) is the amount of tracks that were correctly categorized to the right genre. The recall for the horror tracks is best, with a total accuracy of 75%. So 75% of the tracks that belong to Horror films, are correctly categorized. The precision and recall is lowest for Action movies.

Self-similarity marices of a horror outlier [Chroma and Timbre]